好吧,我有一个包装器类工作。它计算实时传递。首先,它比较UTC的偏移量,并将此时间差与作为参数传递的datetime对象相加或相减。此后,它只需要调用parent::diff就可以了。好吧,我需要引入一个一行程序来破解PHP中的另一个bug(请参阅下面的源代码)。DateTimeDiff:差分法计算实时传递。为了理解这意味着什么,我建议您使用各种不同的日期和时间来测试这个类,并且为了帮助您的工作量,我在这个注释的底部还包括了一个我编写的非常简单的HTML页面。此链接可以作为获取日期和时间组合的一些想法的良好起点:
https://wiki.php.net/rfc/datetime_and_daylight_saving_time
此外,请注意,当我们在DST中进行向后转换时,一些日期/时间组合可能属于这两个时区。这种模糊性会使这个类的结果与预期的不同。因此,如果您认真考虑使用这个类,请进一步开发它,并在这些情况下要求用户澄清。
给你,同学们:
<?php
class DateTimeDiff extends DateTime
{
public function diff($datetime, $absolute = false)
{
// Future releases could fix this bug and if so, this method would become counterproductive.
if (version_compare(PHP_VERSION, '5.4.0') > 0)
trigger_error("You are using a PHP version that might have adressed the problems of DateTime::diff", E_USER_WARNING);
// Have the clock changed?
$offset_start = $this->getOffset();
$offset_end = $datetime->getOffset();
if ($offset_start != $offset_end)
{
// Remember the difference.
$clock_moved = $offset_end - $offset_start;
// We wouldn't wanna mess things up for our caller; thus work on a clone.
$copy = clone $datetime;
if ($clock_moved > 0)
{
$timestamp_beforesub = $copy->getTimestamp();
// Subtract timedifference from end-datetime should make parent::diff produce accurate results.
$copy->sub( DateInterval::createFromDateString("$clock_moved seconds") );
// No change occured; sometimes sub() fails. This is a workable hack.
if ($timestamp_beforesub == $copy->getTimestamp())
$copy->setTimezone(new DateTimeZone("UTC"));
}
else // ..else < 0 and its a negative.
{
$clock_moved *= -1;
// Adding that timedifference to end-datetime should make parent::diff produce accurate results.
$copy->add( DateInterval::createFromDateString("$clock_moved seconds") );
}
return parent::diff($copy, $absolute);
} // <-- END "if ($offset_start != $offset_end)"
return parent::diff($datetime, $absolute);
}
}
?>
以及用于测试的页面(将显示同时使用DateTime::diff和DateTimeDiff::diff的结果):
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>DateTimeDiff-class</title>
<?php
if (! (empty($_GET['identifier']) && empty($_GET['start']) && empty($_GET['end'])))
{
$dt1_new = new DateTimeDiff("{$_GET['start']} {$_GET['identifier']}");
$dt1_old = new DateTime("{$_GET['start']} {$_GET['identifier']}");
$dt2 = new DateTime("{$_GET['end']} {$_GET['identifier']}");
$di_new = $dt1_new->diff($dt2);
$di_old = $dt1_old->diff($dt2);
// Extract UNIX timestamp and transitional data
$timezone_start = $dt1_new->getTimezone();
$timezone_end = $dt2->getTimezone();
$timestamp_start = $dt1_new->getTimeStamp();
$timestamp_end = $dt2->getTimeStamp();
$transitions_start = $timezone_start->getTransitions($timestamp_start, $timestamp_start);
$transitions_end = $timezone_end->getTransitions($timestamp_end, $timestamp_end);
echo <<<BUILDCONTAINER
<script type='text/javascript'>
function Container() { }
var c_new = new Container;
var c_old = new Container;
var t_start = new Container;
var t_end = new Container;
</script>
BUILDCONTAINER;
echo <<<SETTRANSITIONS
<script type='text/javascript'>
t_start.ts = '{$transitions_start[0]['ts']}';
t_start.time = '{$transitions_start[0]['time']}';
t_start.offset = '{$transitions_start[0]['offset']}';
t_end.ts = '{$transitions_end[0]['ts']}';
t_end.time = '{$transitions_end[0]['time']}';
t_end.offset = '{$transitions_end[0]['offset']}';
</script>
SETTRANSITIONS;
foreach ($di_new as $property => $value)
echo "<script type='text/javascript'>c_new.$property = $value</script>";
foreach ($di_old as $property => $value)
echo "<script type='text/javascript'>c_old.$property = $value</script>";
}
?>
<script type='text/javascript'>
window.onload = function()
{
if (c_new != null) // <-- em assume everything else is valid too.
{
// Update page with the results
for (var prop in c_new)
addtext(prop + ": " + c_new[prop] + " (" + c_old[prop] + ")");
addtext("Read like so..");
addtext("PROPERTY of DateInterval: VALUE using DateTimeDiff::diff ( VALUE using DateTime::diff )");
// Restore values sent/recieved
<?php
foreach ($_GET as $key => $value)
echo "document.getElementById('$key').value = '$value';";
?>
// Display transitiondata (For DateTime start)
var p_start = document.getElementById('p_start');
var appendstring = "TS: " + t_start.ts + ", Time: " + t_start.time + ", Offset: " + t_start.offset;
p_start.appendChild(document.createTextNode(appendstring));
// Display transitiondata (For DateTime end)
var p_end = document.getElementById('p_end');
appendstring = "TS: " + t_end.ts + ", Time: " + t_end.time + ", Offset: " + t_end.offset;
p_end.appendChild(document.createTextNode(appendstring));
}
}
function addtext()
{
var p = document.createElement("p");
p.appendChild(document.createTextNode(arguments[0]));
document.forms[0].appendChild(p);
}
</script>
</head>
<body>
<form action="test2.php" method="get">
<p>Identifier: <input type="text" name="identifier" id="identifier" value="Europe/Stockholm" /></p>
<p id="p_start">Start: <input type="text" name="start" id="start" /></p>
<p id="p_end">End: <input type="text" name="end" id="end" /></p>
<p><input type="submit" /></p>
</form>
</body>
</html>
